Covers for medical probes are well known and come in various designs. For example, in Fraden et al. U.S. Pat. No. 5,163,418, a speculum cover for an infrared thermometer is disclosed, where a pleated cover surrounds the probe that is inserted into the ear, for example, for taking of a body temperature by measurement of infrared (IR) radiation.
A similar probe is disclosed in O'Hara et al. U.S. Pat. No. 5,179,936, in which an ear canal probe of a tympanic thermometer has a cover comprising a molded plastic sheath with a separate front membrane which is made of IR transparent material.
As a disadvantage, potentially the best IR transparent, flat plastic films such as polyethylene have common ingredients added to reduce the surface tack, which can interfere with IR transparency. Such materials without such ingredients thus exhibit an undesirable surface tack, so that sheaths made of such a material are difficult to use. Also, structures which are pleated, or which have a separate front end made of a different, IR transparent material bonded to the rest of the sheath, are difficult to reliably manufacture so that they do not tend to break or fail in use. Thus their cost is undesirably high.
By this invention, inexpensive, easily manufactured probes are provided in which plastic materials of the highest infrared or other radiation transparencies can be used without interfering with the ease of use of the probe sheath, or a diminishment of its reliability.